Which type of hairs do not react favorably to laser hair reduction?

• A. Gray or non-pigmented hairs
• B. Coarse dark hair
• C. Red hair
• D. Pigmented hair

Answer: (A)

Laser hair reduction relies on melanin in the hair follicle to absorb the laser light and convert it into heat to damage the follicle. Gray or non-pigmented hairs contain little to no pigment, so they don’t absorb enough energy to heat the follicle effectively. As a result, these hairs respond poorly to laser treatment and hair reduction is limited. In contrast, pigmented hairs—especially coarse dark hair—absorb more light and respond well, while red hair has less pigment and can be more challenging to treat. The key idea is that the presence of pigment in the hair determines how well the laser energy is absorbed and how effective the treatment will be.